What is the most common cause of bronchiolitis in infants?

The most common cause of bronchiolitis in infants is Respiratory Syncytial Virus (RSV). RSV is highly contagious and primarily affects children under the age of two, especially those who are very young or have underlying health conditions. The virus leads to inflammation and obstruction of the small airways in the lungs, causing symptoms such as wheezing, coughing, and difficulty breathing.

RSV typically peaks during the fall and winter months, coinciding with the cold season, and it's responsible for the majority of hospitalizations due to bronchiolitis in infants. The prevalence and significant impact of RSV on pediatric patient populations underscore its importance in respiratory illnesses among young children, making it the leading viral cause of bronchiolitis.

Other viruses, such as parainfluenza virus, rhinovirus, and adenovirus, can also cause respiratory illnesses in infants but are less commonly linked to bronchiolitis compared to RSV. Understanding the dominant role of RSV in bronchiolitis can help guide diagnostic and treatment approaches in pediatric care.